merge: testing → main (reconcile 2-week divergence)

tests/realism/test_circuit_breaker.py

@@ -0,0 +1,81 @@
+"""LLMCircuitBreaker — process-local sliding-window breaker."""
+from __future__ import annotations
+
+from decnet.realism.llm.circuit import LLMCircuitBreaker
+
+
+def test_starts_closed_and_allows_calls() -> None:
+    breaker = LLMCircuitBreaker()
+    assert breaker.state == "closed"
+    assert breaker.allow_call() is True
+
+
+def test_trips_open_after_threshold_failures() -> None:
+    clock_value = [0.0]
+    breaker = LLMCircuitBreaker(
+        failure_threshold=3, cooldown_seconds=60.0,
+        clock=lambda: clock_value[0],
+    )
+    breaker.record_failure()
+    assert breaker.state == "closed"
+    breaker.record_failure()
+    assert breaker.state == "closed"
+    breaker.record_failure()
+    assert breaker.state == "open"
+    assert breaker.allow_call() is False
+
+
+def test_success_resets_consecutive_failure_count() -> None:
+    breaker = LLMCircuitBreaker(failure_threshold=3)
+    breaker.record_failure()
+    breaker.record_failure()
+    breaker.record_success()
+    breaker.record_failure()
+    breaker.record_failure()
+    assert breaker.state == "closed"  # only 2 since the success
+
+
+def test_half_open_after_cooldown() -> None:
+    clock_value = [0.0]
+    breaker = LLMCircuitBreaker(
+        failure_threshold=2, cooldown_seconds=10.0,
+        clock=lambda: clock_value[0],
+    )
+    breaker.record_failure()
+    breaker.record_failure()
+    assert breaker.state == "open"
+    assert breaker.allow_call() is False
+
+    clock_value[0] = 11.0
+    assert breaker.allow_call() is True
+    assert breaker.state == "half_open"
+
+
+def test_half_open_failure_re_opens() -> None:
+    clock_value = [0.0]
+    breaker = LLMCircuitBreaker(
+        failure_threshold=2, cooldown_seconds=5.0,
+        clock=lambda: clock_value[0],
+    )
+    breaker.record_failure()
+    breaker.record_failure()
+    clock_value[0] = 6.0
+    breaker.allow_call()
+    assert breaker.state == "half_open"
+    breaker.record_failure()
+    assert breaker.state == "open"
+
+
+def test_half_open_success_closes() -> None:
+    clock_value = [0.0]
+    breaker = LLMCircuitBreaker(
+        failure_threshold=2, cooldown_seconds=5.0,
+        clock=lambda: clock_value[0],
+    )
+    breaker.record_failure()
+    breaker.record_failure()
+    clock_value[0] = 6.0
+    breaker.allow_call()
+    breaker.record_success()
+    assert breaker.state == "closed"
+    assert breaker.allow_call() is True